forked from grpc/grpc-go
/
authority.go
229 lines (206 loc) · 6.96 KB
/
authority.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
/*
*
* Copyright 2021 gRPC authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package xdsclient
import (
"errors"
"fmt"
"google.golang.org/grpc/xds/internal/xdsclient/bootstrap"
"google.golang.org/grpc/xds/internal/xdsclient/load"
"google.golang.org/grpc/xds/internal/xdsclient/pubsub"
"google.golang.org/grpc/xds/internal/xdsclient/xdsresource"
)
const federationScheme = "xdstp"
// findAuthority returns the authority for this name. If it doesn't already
// exist, one will be created.
//
// Note that this doesn't always create new authority. authorities with the same
// config but different names are shared.
//
// The returned unref function must be called when the caller is done using this
// authority, without holding c.authorityMu.
//
// Caller must not hold c.authorityMu.
func (c *clientImpl) findAuthority(n *xdsresource.Name) (_ *authority, unref func(), _ error) {
scheme, authority := n.Scheme, n.Authority
c.authorityMu.Lock()
defer c.authorityMu.Unlock()
if c.done.HasFired() {
return nil, nil, errors.New("the xds-client is closed")
}
config := c.config.XDSServer
if scheme == federationScheme {
cfg, ok := c.config.Authorities[authority]
if !ok {
return nil, nil, fmt.Errorf("xds: failed to find authority %q", authority)
}
config = cfg.XDSServer
}
a, err := c.newAuthority(config)
if err != nil {
return nil, nil, fmt.Errorf("xds: failed to connect to the control plane for authority %q: %v", authority, err)
}
// All returned authority from this function will be used by a watch,
// holding the ref here.
//
// Note that this must be done while c.authorityMu is held, to avoid the
// race that an authority is returned, but before the watch starts, the
// old last watch is canceled (in another goroutine), causing this
// authority to be removed, and then a watch will start on a removed
// authority.
//
// unref() will be done when the watch is canceled.
a.ref()
return a, func() { c.unrefAuthority(a) }, nil
}
// newAuthority creates a new authority for the config. But before that, it
// checks the cache to see if an authority for this config already exists.
//
// caller must hold c.authorityMu
func (c *clientImpl) newAuthority(config *bootstrap.ServerConfig) (_ *authority, retErr error) {
// First check if there's already an authority for this config. If found, it
// means this authority is used by other watches (could be the same
// authority name, or a different authority name but the same server
// config). Return it.
configStr := config.String()
if a, ok := c.authorities[configStr]; ok {
return a, nil
}
// Second check if there's an authority in the idle cache. If found, it
// means this authority was created, but moved to the idle cache because the
// watch was canceled. Move it from idle cache to the authority cache, and
// return.
if old, ok := c.idleAuthorities.Remove(configStr); ok {
oldA, _ := old.(*authority)
if oldA != nil {
c.authorities[configStr] = oldA
return oldA, nil
}
}
// Make a new authority since there's no existing authority for this config.
ret := &authority{config: config, pubsub: pubsub.New(c.watchExpiryTimeout, c.logger)}
defer func() {
if retErr != nil {
ret.close()
}
}()
ctr, err := newController(config, ret.pubsub, c.updateValidator, c.logger)
if err != nil {
return nil, err
}
ret.controller = ctr
// Add it to the cache, so it will be reused.
c.authorities[configStr] = ret
return ret, nil
}
// unrefAuthority unrefs the authority. It also moves the authority to idle
// cache if it's ref count is 0.
//
// This function doesn't need to called explicitly. It's called by the returned
// unref from findAuthority().
//
// Caller must not hold c.authorityMu.
func (c *clientImpl) unrefAuthority(a *authority) {
c.authorityMu.Lock()
defer c.authorityMu.Unlock()
if a.unref() == 0 {
configStr := a.config.String()
delete(c.authorities, configStr)
c.idleAuthorities.Add(configStr, a, func() {
a.close()
})
}
}
// authority is a combination of pubsub and the controller for this authority.
//
// Note that it might make sense to use one pubsub for all the resources (for
// all the controllers). One downside is the handling of StoW APIs (LDS/CDS).
// These responses contain all the resources from that control plane, so pubsub
// will need to keep lists of resources from each control plane, to know what
// are removed.
type authority struct {
config *bootstrap.ServerConfig
pubsub *pubsub.Pubsub
controller controllerInterface
refCount int
}
// caller must hold parent's authorityMu.
func (a *authority) ref() {
a.refCount++
}
// caller must hold parent's authorityMu.
func (a *authority) unref() int {
a.refCount--
return a.refCount
}
func (a *authority) close() {
if a.pubsub != nil {
a.pubsub.Close()
}
if a.controller != nil {
a.controller.Close()
}
}
func (a *authority) watchListener(serviceName string, cb func(xdsresource.ListenerUpdate, error)) (cancel func()) {
first, cancelF := a.pubsub.WatchListener(serviceName, cb)
if first {
a.controller.AddWatch(xdsresource.ListenerResource, serviceName)
}
return func() {
if cancelF() {
a.controller.RemoveWatch(xdsresource.ListenerResource, serviceName)
}
}
}
func (a *authority) watchRouteConfig(routeName string, cb func(xdsresource.RouteConfigUpdate, error)) (cancel func()) {
first, cancelF := a.pubsub.WatchRouteConfig(routeName, cb)
if first {
a.controller.AddWatch(xdsresource.RouteConfigResource, routeName)
}
return func() {
if cancelF() {
a.controller.RemoveWatch(xdsresource.RouteConfigResource, routeName)
}
}
}
func (a *authority) watchCluster(clusterName string, cb func(xdsresource.ClusterUpdate, error)) (cancel func()) {
first, cancelF := a.pubsub.WatchCluster(clusterName, cb)
if first {
a.controller.AddWatch(xdsresource.ClusterResource, clusterName)
}
return func() {
if cancelF() {
a.controller.RemoveWatch(xdsresource.ClusterResource, clusterName)
}
}
}
func (a *authority) watchEndpoints(clusterName string, cb func(xdsresource.EndpointsUpdate, error)) (cancel func()) {
first, cancelF := a.pubsub.WatchEndpoints(clusterName, cb)
if first {
a.controller.AddWatch(xdsresource.EndpointsResource, clusterName)
}
return func() {
if cancelF() {
a.controller.RemoveWatch(xdsresource.EndpointsResource, clusterName)
}
}
}
func (a *authority) reportLoad(server string) (*load.Store, func()) {
return a.controller.ReportLoad(server)
}
func (a *authority) dump(t xdsresource.ResourceType) map[string]xdsresource.UpdateWithMD {
return a.pubsub.Dump(t)
}